During the production of thin-film LEDs (light-emitting diodes or luminous diodes using thin-film technology), the layer structure provided therefor is produced epitaxially on an epitaxy substrate. The epitaxy substrate is sapphire, for example, but can also be GaN, SiC, silicon, AlN or corresponding equivalent (for the growth of AlGaInN layer structures), GaAs, Ge or corresponding equivalent (for the growth of AlGaInP layer structures or AlGaAs layer structures) or InP (for the growth of InGaAsP layer structures). The thin-film LED structure is transferred to a carrier, e.g. composed of germanium, by connection contact areas of the LED structure, which are usually formed by a layer composed of Ti/Pt/Au, being soldered on a corresponding contact area of the carrier. The epitaxy substrate can subsequently be removed. The thin-film LED is then permanently fixed on the carrier and thus forms a component which can be mounted in an envisaged manner in a housing, by way of example.
A multiplicity of individual LEDs are produced on the epitaxy substrate. The layer structure of the thin-film LEDs therefore has to be subdivided into the individual LEDs. For this purpose, trenches are etched into the epitaxial layers, with the result that so-called mesas remain which are respectively assigned to an LED to be produced. In order to connect the connection contact areas of said mesas to the top side of the carrier, a solder layer is usually applied to the carrier over the whole area. During such a soldering process, solder material can be applied, in principle, to both contact areas to be connected to one another.
During soldering, the carrier and the epitaxy substrate are pressed onto one another with the contact areas facing one another. In this case, solder penetrates in an undesired manner into the trench between the mesas and forms irregular beads there. These irregularities during production cause losses in the yield of functional components and an increased outlay in the monitoring of mass production, which increases the manufacturing costs. These difficulties can be avoided e.g. by the mesas being etched only after connection to the carrier. Instead of this, it is also possible to structure the carrier in accordance with the LED mesas and, in this way, to keep the trench between the mesas free of solder; however, that requires an accurate alignment of the carrier on the epitaxy substrate.
Materials and methods of isothermal solidification which are suitable for the soldering of electronic components are described in detail in the article by Rainer Schmid-Fetzer: “Fundamentals of Bonding by Isothermal Solidification for High Temperature Semiconductor Applications” in R. Y. Lin et al. (eds.): “Design Fundamentals of High Temperature Composites, Intermetallics, and Metal-Ceramics Systems”, The Minerals, Metals & Materials Society, 1995, pages 75 to 98.
DE 10 2007 030 129 specifies a method for producing a plurality of optoelectronic components. Said method comprises providing a connection carrier assemblage having a plurality of component regions, in each of which at least one electrical connection region is provided, and also providing a semiconductor body carrier, on which a plurality of separate semiconductor bodies connected to the semiconductor body carrier are arranged, wherein the semiconductor bodies each have a semiconductor layer sequence with an active region. The connection carrier assemblage and the semiconductor body carrier are oriented relative to one another in such a way that the semiconductor bodies face the component regions. A plurality of semiconductor bodies are mechanically connected to the connection carrier assemblage in a mounting region of a component region assigned to the respective semiconductor body, and the respective semiconductor body is electrically conductively connected to the connection region of the component region assigned to the semiconductor body. The semiconductor body connected to the connection carrier assemblage is separated from the semiconductor body carrier, and the connection carrier assemblage is divided into a plurality of separate optoelectronic components each having a connection carrier, which has the component region, and a semiconductor body arranged on the connection carrier and electrically conductively connected to the connection region.